1. Field of the Invention
The present invention relates to a surface texture measuring probe adaptable to a near-field scanning optical microscope (NSOM), an atomic force microscope (AFM) and a scanning tunneling microscope (STM), as well as a microscope utilizing the surface texture measuring probe.
2. Description of Related Art
An optical microscope has been known as an example of a near-field scanning optical microscope for measuring surface texture of a workpiece utilizing evanescent light (near-field light), which is disclosed in Document 1 (JP-A-2001-165843).
The optical microscope includes a light irradiator that irradiates light on a surface of a sample, a cantilever holding a probe, and an objective optical system that receives scattered light caused by incident light generated at a tip end of the probe. The cantilever is provided with a holder base, which is a fixed end, a probe holder arranged on the holder base to extend in one direction, and the probe disposed on a free end of the probe holder.
According to the above-described near-field scanning optical microscope, since the incident light incident on the surface of the sample is scattered by the extremely small probe and the scattered light is received and detected by the objective optical system, disturbance vibration likely affects on the probe, thus extremely deteriorating measurement accuracy.
To solve this, there is suggested a measuring method with the probe vibrated. However, since the cantilever structure anchored by the holder base as the fixed end is employed for the conventional probe, which causes flexural vibration, the natural frequency fc cannot be heightened. Generally, when the position of the probe etc. is controlled in accordance with the feedback fed by a sensor, if the control is based on the frequency higher than the natural frequency fc, the probe will be oscillated. This is because the phase is rapidly lagged due to the resonance frequency of the sensor as in physical background. Therefore, the conventional cantilever probe does not allow the response speed to be increased, so that the measurement may not be speeded up.